1. Field of the Invention
The present invention relates a zoom lens and an image pickup apparatus equipped with the same.
2. Description of the Related Art
In recent years, digital cameras that pick up an image of an object using an image pickup element such as a CCD or CMOD sensor have replaced film cameras to become the mainstream. Furthermore, various categories of digital cameras ranging from popular-priced compact types to advanced types for professionals have been developed. Among these is a type of camera having a lens with a zoom ratio of about 10 or higher that is accommodated in the camera body when not in use so that it becomes compact.
Zoom lenses having a zoom ratio of about 10 or higher include, for example, a type of zoom lens having, in order from the object side thereof, a first lens unit having a positive refracting power, a second lens unit having a negative refracting power and a third lens unit having a positive refracting power as know from Japanese Patent Application Laid-Open Nos. 11-5244, 11-6958, 2006-171055, 2007-10695 and 2007-3554.